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QN@ Mdem j 24Sheets'-Sheet.2. 1 J. H. BRINGOLD.

BELT TIGHTENER.'

No. 382,587. Patented Maya, 1888.

Witnesses:

UNITED STATES PATENT OFFICE.

JOHN H. BRINGOLD, OF ALBANY, NEXl YORK, ASSIGNOR OF ONE-HALF TO,

`ILLIAM N. PEROY, OF SAME PLACE.

B'ELTQTlG-HTENER.

SPECIFICATION forming part of LEtIefPant No. assassinated May a, Isae. l Application tiled July 19, 1887. Serial No. $244,783. (No model.) i

To LZZ whom it 71mg/ concern:

Beit known that I, JOHN H. BRINGOLD, a citizen of the United States, residing at Albany, in the county of Albany and State of New York, have invented certain new and useful Improvements in Belt -Tighteners for Machines for Dressing Metals, following is a specification.

My-invention relates to improvements in belt-tighteners for machines which employ a revolving shaft for revolving a cutting or dressing wheel or device-as, for instance, for dressing the surfaces of metal plates or pieces; and it consists in the combinations of devices and parts hereinafter described, and specifically set forth in the claim.

The objects of my invention are, first, to provide in machines employing a shaft which is revolved in bearings which are fixed in relation to the main frame of the machine, and on which is mounteda driven pulley and a cutting or dressing wheel or device, a frame which is below the said shaft, and can at will be adjusted in a vertical direction toward or from the same, and be secured so as to hold two pulleys which are fixed in` said frame from moving, and which operate to change -the direction of the endless driving-belt after its portions or halves have been run parts by which my improvement can be put.

downwardly from the driven pulley of the revolving shaft, so that the pullV of the endless belt will he downwardly and in substantially a vertical line on the said shaft, with the said into practice. I attain these objects by the means illustrated in the accompanying drawings, forming a part of this specification, in which- Figure 1 is a sectional elevation of my improvements attached toa machine. Fig. 2 is a transverse sectional viewof the same. Fig.

3 is a cross-sectional View taken at line 1 in of which they Fig. 2. Fig. 4. is aside elevation, on asmaller scale, of'a machine carrying an emery-whe'el and a brush-wheel, and having my improve;l ments connected therewith, the shaft of the machine being providedwith yielding or elastic bearings. Fig. 5 is an elevation of the same, and illustrating my improvements con'- 4nected therewith, and taken at line2 in Fig. 4.

The same letters of reference refer to similar parts throughout the several views.

In the drawings, A represents the framework of an emery-wheel or brush-wheel, which frame can be of any known form of construe tion.

B" is the revolving shaft which carries the emery-wheelb or wirebrushvwheel b', or both, or a bufting-wheel or equivalent wheel for dressing or linishing the surfaces -of metal.

`In Figs. 1 and 2 the machine is shown to be provided with an unyielding wheel-shaft, B, the ,shaft being held in rigid bearings. In Figs. 4 and 5 this shaft is shown to be supported in flexible or elastic bearings. j

C is'the driven pulley on shaft B, and is revolved by belt D, which is actuated by any suitable driving-wheel from a countershaft or other suitable shaft. i

F. is a pulleyframe, which consists lin its essential parts or elements of the side pieces, e e, and end pieces, e' e,and the bearingsk or boxes c c.

Fand Gare pulleys mounted on shaftsfand g, respectively, which shafts have bearing in boxes o c. In practice I prefer to make the upper pulley, F, smaller than the lower pulley; yet these pulleys can be made of the same size.

The drawings, Figs. 2 and 3, show these pulleys F and G to be loosely mounted on their respective shaftsj' and g. While these shafts are themselves free to revolve in their respective bearings or boxes c c, yet, if desired, these pulleys can be fixed on their respective shafts, while 'the latter are free to revolve; or the pulleys can be loose to revolve while the shafts can be Xed. The bearings of these shafts f and g can be of any known form of construction, and be made with the side pieces, e e, or attached thereto. y

H is a guiding-frame of any suitable form of 10o construction, which will be capable of beingv or beneath the pulley C on the shaft B. This guiding-frame is shown to be composed of the side pieces, h h, having in them slots i,which extend in a vertical direction, so as to receive the tongues or projections d d, made with the side pieces, e e, of the pulley-frame E, for holdlng and guiding the latter. These pieces h are shown to be secured to the crossbars I and J of the machine by bolts; yet they can be secured to the frame of the machine in any suit able manner.

K is a spring having sucient strength to lift the pulley-frame E and its adjuncts. This spring is arranged between the pulley-fran1e E and the guiding-frame H, so as to raise the former in relation to the latter.

L is an adjusting setbolt, provided with a head on one end and a screw-threaded nut, Z, on the other, and made with a length suicient to allow the frame E to be raised to its full height in relation to frame H. This bolt is shown to pass from above through the lower end bar, e', of the pulley-frame E, and through spring K and the lower end bar of the guidingframe H, with the nut Z screwed on the lower portion of the bolt against the lower side of the lower cross;pieceeeframegH, as shownin."

Figs. 1 and 2.Yet, if desired,`"ithespri''g K can be employed with the bolt L reversed, and provided with two nuts similar to nut l, with one of the nuts working upwardly against the lower side of the lower end piece, e, of the pulley-frame E and the other on the upper side of the same.

When the guidingframeH has been secured to the main frame of the machine and the pulley-frame has been placed in position in said guiding-frame, the pulleysF and G will be relatively below pulley C on the operatingshaft B, as shown. rIhe nut Z on the adjusting-bolt L will be loosened to allow the pulley-frame to be raised, and the belt D will pass from the counter-shaft pulley or wheel, or other suitable driving pulley or wheel, (not shown,) to the under side of lower pulley, G, and thence upwardly to and around pulley C on the operating-shaft B, and thence downwardly and on the lower side of the upper pulley, F, and thence to and around the driving pulley or wheel (not shown) or point of beginning, all substantially as indicated by arrows in Fig. 1. The operator will then tighten the pulleys F and G on belt D by means of the adjusting-bolt L and its nut l, which will be done by turning nutlin direc tion to draw the pulley-frame E downwardly in relation to its guiding-frame H, 'when the belt D will be made to pull tightly on pulley C on shaft B and 'cause the journals of tlie latter to lie close at the bottoms of their respective bearings or boxes, when the machine will be ready for operation.

In operation the belt D is pulled d own on pulley C, and the shaft of said pulley is made to run or revolve rapidly without any jumping or tendency to jump when the pressure on the emery-wheel or brush-wheel or polishingwheel is increased or lessened, which is of great advantage, as the journals ofthe wheel-shaft B will in all cases run at the bottoms of the bearings or boxes with a sucient amount of elasticity between the belt and the several pulleys to prevent the shaft B being absolutely B will revolve steadily when the bearings and journals become worn, and when used with elast-ically-supported wheel-shafts, asshown in Figs. 4 and 5, these improvements operate to hold that shaft B from having excessive lateral movement, so that the use of -the side set screws to limit such lateral movement of said shaft are obviated, and the shaft is made to run steady under great or less pressure on the wheels b b.

In the rapid wear attending thejournals and bearings or boxes of the shaft B in machines `for grinding, polishing, or .dressing surfaces of metal there is required to be expended a considerable amount of care and labor to keep these parts in repair and in condition to do ordinarily good work. By my above-described improvements the wear of those parts will not materially affect the working of the machine, and no particular care or attention is required to preserve in the machine the proper conditions of the revolving shaft B for producing the best of work or results.

Havingdescribed my invention, what I claim, and desire to secure by Letters Patent, is-

The combination of the guiding-frame H, se-

i z', the pulley-frame E, carrying pulleys F and G, and provided with projections d d, working in said slot-s, adjustingbolt L, and spring K between said guiding-frame and the pulleyframe, with the pulley C of the wheel operating shaft B and the belt D, substantially as and for the purposes set forth.

`JOHN H. BRINGOLD.

Witnesses:

ALEX. SELKIRK, CHARLES SELKIRK.

rigid. By this improvement the wheel-shaft cured to the machine and provided with slots IIO 

